Project Descriptions for the 2023 REU Program

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Last updated on 12/07/2022

Nature-Inspired, Computationally Designed Materials (Soft Materials)

Interdisciplinary Research Group 1: Peptide Active Materials (PAMs)

Solution assembly of bundlemer peptide nanoparticles w/ Dr. Pochan

Faculty mentor: Prof. Darrin Pochan
Graduate student mentor: Matt Langenstein
🔗 Research Group Site

We are creating new nanoscale building blocks to build new soft matter and polymeric materials. The building blocks are created with peptides that assemble in solution to form coiled coil bundles, called ‘bundlemers’. We use these nanoparticles to build interesting polymer chains as well as 2-dimensional sheets and 3-dimensional lattices with interesting mechanical properties as well as with inherent environmental compatibility being made out of amino acids. The project will involve learning peptide synthesis, molecular characterization, and solution assembly behavior. With a solid understanding of the bundlemer assembly and solution behavior, these building blocks will be connected together in order to build new nanomaterials.

Scalable biosynthesis of peptide building blocks and nanomaterials w/ Dr. April Kloxin

Faculty mentor: Prof. April Kloxin
Graduate student mentor: Caitlin D’Ambrosio
🔗 Research Group Site

We have established approaches for biosynthesis of peptide building blocks and now would like to scale up this process for making bulk building blocks and nanomaterials. The student working on this project will aim to optimize bioreactor operations for scaling up the bio manufacturing of these materials. This project will involve learning and utilizing skills in bacterial culture, bioreactors, column chromatography, and peptide and materials characterization relevant to a range of applications.

Production of bioelastomeric springs for molecular actuators w/ Dr. Kiick

Faculty mentor: Prof. Kristi Kiick
Graduate student mentors: Sai Patkar & Bin Wang
🔗 Research Group Site

Themoresponsive polypeptides have many applications in the production of hydrogels, drug delivery systems, and actuating materials. One potential application of these polymers is as a responsive element in the assembly properties of rod-like materials. This summer project will explore the production of novel thermoresponsive polypeptides, and characterization of their solution and surface behavior, via spectroscopic and microscopy methods.

Design light-responsive bundlemers w/ Dr. Chen

Faculty mentor: Prof. Wilfred Chen
Postdoctoral researcher mentor: Nadim Massad
🔗 Faculty Page

Recombinant production of bundlemers for light-responsive actuation.

Bundlemers: Towards the creation of a molecular Lego w/ Dr. Christopher Kloxin

Faculty mentor: Prof. Christopher Kloxin
Graduate student mentor: Joshua Meisenhelter
🔗 Research Group Page

Molecular structures found in nature are built upon common reoccurring substructural units, such as alpha helices and beta sheets; in contrast, most synthetic polymers lack such modular design and are less functionally sophisticated. This research project aims to develop a new approach for designing and preparing complex polymeric nanostructures using short peptide sequences that assemble into robust and well-defined coil-coil units called bundlemers. Here, we will implement new functionalization and crosslinking strategies towards realizing the bundlemer as a fundamental building block, or ‘molecular Lego’, to create complex targeted nanomaterials. The student working on this project will learn an array of small molecule and macromolecular synthetic methods (from non-natural amino acid synthesis to microwave solid phase peptide synthesis and polymer-peptide conjugations) and characterization techniques (from NMR and mass spec to scattering and TEM).

Bioorthogonal syntheesis of peptide assemblies with tunable rigidity w/ Dr. Jia

Faculty mentor: Prof. Xinqiao Jia
Graduate student mentor: Hanyuan Gao
🔗 Research Group Page

We are interested in developing supramolecular peptide assembly with tunable persistent length. The peptidic building blocks capable of forming coiled-coil 4-helical bundles (“bundlemer”) are produced via solid phase peptide synthesis and chemically addressable functional groups that participate in tetrazine ligation, an efficient, rapid and bioorthogonal cycloaddition reaction between tetrazines (Tz) and trans-cyclooctenes (TCO), are introduced after the peptide is cleaved from the solid support. Step growth polymerization is performed using bundlemers carrying complementary Tz and TCO functionalities in solution or at the interface between two immiscible aqueous phases. When the bioorthogonal handles are coupled to the bundlemer via a short flexible PEG linker, the resultant supramolecular assembly is relatively flexible. We anticipate that if the reactive handles are introduced to the bundlemer directly through the N-terminus without any spacer, the resultant assembly will likely be rigid with long persistent length. The supramolecular assemblies are analyzed by circular dichroism (CD), transmission electron microscopy (TEM), gel electrophoresis and size exclusion chromatography (SEC).

Bioorthogonal Chemistry and Bundlemers w/ Dr. Fox

Faculty mentor: Prof. Joseph Fox
Graduate student mentor: Sirajis Salekin
🔗 Research Group Page

Tetrazine ligation, first developed here at UD, is the fastest known bioorthogonal reaction, and provides a unique handle for the polymerization of peptide-based helical monomers, and for the preparation of peptide-protein hybrid materials. REU students will have the opportunity to learn skills ranging from organic synthesis to protein chemistry in this project.

Fabrication and characterization of peptide-hydrogel nanocomposites w/ Dr. Korley

Faculty mentor: Prof. LaShanda Korley
Graduate student mentor: Jessica Thomas
🔗 Research Group Page

Hydrogels are an attractive material platform for applications in tissue engineering due to their general biocompatibility and ability to retain large amounts of water, thus mimicking some properties of natural tissues. However, synthetic hydrogels often lack the robust mechanical strength required for prolonged performance. This challenge may be mitigated by the use of high-strength additives to polymer networks to create composite gels. The goal of this project is to incorporate exceptionally rigid peptide rod assemblies into covalent networks to reinforce the polymer matrix while maintaining biocompatibility. Additionally, the inclusion of these nanoscale peptide coiled-coils allows for the introduction of stimuli responsive properties into the composite, as assembly is reversible through varying parameters such as temperature or pH. Covalent networks will be formed through a UV cure process, further expanding the utility of this system to additive manufacturing processing methods. Compression experiments will be performed in order to assess the effect of peptide rods on network strength. Differences in hydrogel morphology will be probed using scanning electron microscopy (SEM). These experiments will investigate the impact of a novel nanofiller on critical properties of hydrated networks.

Fabrication and characterization of photoconductive switch materials and devices w/ Dr. Zide

Faculty mentor: Prof. Joshua Zide
Graduate student mentor: Wilder Acuna
🔗 Research Group Page

III-V materials grown by molecular beam epitaxy (MBE) are extremely promising for photoconductive switches, which can be used as terahertz sources and detectors. This project, in close collaboration with PhD student Wilder Acuna, focuses on characterization of these materials (and devices made from them) to understand properties required for terahertz applications. Some specific techniques include Hall effect measurements for electrical characterization, high-resolution x-ray diffraction (HR-XRD) to determine epitaxial film quality, and atomic force microscopy (AFM) to analyze surface quality. Additionally, we hope to do some work on fabrication and characterization of photoconductive switches. The student will also learn about MBE, a technique that allows the growth of high quality single-crystal semiconductors with exquisite control, including the ultrahigh vacuum technology that enables it and the mechanisms to control material composition and morphology.

Optical Characterization of Hybrid Materials w/ Dr. Doty

Faculty mentor: Prof. Matthew Doty
Graduate student mentor: Charles Ameyaw
🔗 Research Group Page

One of the primary goals of the research by our IRG team is to develop hybrid materials that have optical and electronic functionality that goes beyond what can be achieved in any single material. We are particularly interested in the THz frequency regime, which is a portion of the electromagnetic spectrum in the extreme infrared that has many applications in biomedical imaging, security screening, and wireless communications. A big limitation on the use of THz frequencies is the lack of a single material platform that can provide all the functions required for a device. For example, III-V semiconductors such as GaAs can be very efficient sources and detectors of THz radiation, but they make very poor waveguides because they are transparent to THz radiation. In contrast, Topological Insulators are good at routing plasmons in the THz frequency range, but they are not good for generating or detecting these excitations. One goal for a hybrid material would be to combine generation, routing, and detection of THz frequency excitations in a single material platform. This project will focus on using ultrafast optical methods to measure the THz absorption and emission of hybrid materials synthesized by other members of our team. From this data we can understand the interactions between the constituents that make up the hybrid. The student will learn how to use ultrafast (pulsed) lasers, how to conduct optical experiments, how to analyze data, and how to work together as a team to understand the results.

Ultrafast THz dynamics in quantum materials w/ Dr. Gundlach

Faculty mentor: Prof. Lars Gundlach
Graduate student mentor: Weipeng Wu
🔗 Research Group Page

Understanding the interaction between novel hybrid materials and THz radiation on time-scales as short as picoseconds is important for designing new and improving existing THz materials and devices. In this project the techniques and instrumentation necessary for measuring ultrafast THz response are applied, improved and developed. One focus of this project lies on implementing polarization-, temperature- and magnetic field-control in visible pump – THz probe spectroscopy. Students will work closely with the PhD student overseeing the project. They will be introduced to working with advanced ultrafast optical instrumentation and how to modify it for specific measurements. Students will learn how to conduct ultrafast time-resolved spectroscopic measurements, analyze the acquired data, and interpret the results.

Discover Alter Magnetic Materials w/ Dr. Xiao

Faculty mentor: Prof. John Xiao
Graduate student mentor: Subhash Bhatt
🔗 Research Group Page

The project is to investigate emerging altermagnetic materials (AMs), a group of antiferromagnetic materials (AFMs) with spin-momentum locking, i.e. electrons with aligned spin direction when flowing along a particular crystal direction. AFMs, in contrasting with ferromagnetic materials (FMs) which are widely used in modern information storage and processing, possess zero net magnetization due to their two magnetic crystal sublattices being antiparallel-aligned. Although AFMs have salient features over FMs in applications, such as three orders of magnitude enhanced operation speed (from GHz to THz) and immunity to electromagnetic interference, the challenges are daunting since AFMs lack physical observables (resistance, voltage, etc.) that are related to their magnetization direction, known as the Néel vector defined as the difference the magnetization vectors of two sublattices. Most recently, the development of AMs featuring spin-momentum locking properties allows the direct replacement of FMs with AMs in current device architectures based on giant and tunneling magnetic resistance (GMR and TMR, respectively) phenomena.

Development of quantum sensors for the study of quantum materials w/ Dr. Ku

Faculty mentor: Prof. Mark Ku
Graduate student mentor: Hang Chen
🔗 Research Group Site

Recent years have witnessed the rise of exotic phenomena in materials that are the results of complex collective behaviors which cannot be predicted from the properties of individual electrons alone. Understanding such materials – also known as quantum materials – is a frontier science and will enable engineering and control of novel material properties critical for next generation devices. However, elucidating many of the exotic behaviors of these quantum materials demand new probe capability. In this project, we seek to develop new techniques to probe quantum materials based on quantum sensors realized with artificial atoms in solids, including nitrogen vacancy (NV) centers in diamond and boron vacancy (VB) in 2D material hexagonal boron nitride (hBN). Our vision is to provide enabling tools to study materials of interest to MRSEC IRG2, including antiferromagnets, altermagnets, 2D magnets, and topological materials. Activities for the student may include constructing parts for quantum sensing setup, operating the setup for measurement, and analyzing data. The student will learn how to work with opto/mechanical/electronic components of an experimental setup, conducting quantum science experiments, and interpreting results.

Magnon interactions in synthetic and layered antiferromagnets w/ Dr. Jungfleisch

Faculty mentor: Prof. Benjamin Jungfleisch
Graduate student mentors: Tomal Hossain & Weipeng Wu
🔗 Research Group Page

Antiferromagnetic spintronics and magnonics offer distinct advantages over their ferromagnetic counterparts since they are robust against charge and magnetic field perturbations. Antiferromagnets (AFMs) exhibit zero net magnetization and therefore lack stray fields, which enables high-density storage concepts. Synthetic AFMs and van der Waals (vdW) AFMs can serve as a model system for studying AFM ordering and magnon excitations. This project will focus on the characterization of synthetic AFMs and vdW AFMs by microwave spectroscopy and time-domain THz spectroscopy. In particular, the student will work on magnetic-field dependent THz emission in these systems providing the potential for realizing magnon-based hybrid systems. The student will learn how to conduct optical and microwave experiments, how to analyze and interpret the data, and how to model the experimental results.

Dynamically tunable THz metamaterials w/ Dr. Wang

Faculty mentor: Prof. Xi Wang
Graduate student mentor: Zhixiang Huang
🔗 Faculty Page

This project aims to demonstrate dynamically tunable THz metamaterials, which are artificial structure with subwavelength features. THz metamaterials manipulate the properties of incident THz light, tuning its intensity, phase, and/or polarization. The REU student will focus on numerical simulations to model several THz metamaterials. In addition, the REU student will work with the mentor to analyze collected experimental data.